High-efficiency vertically emitting coupler facilitated by three wave interaction gratings.

We designed a grating coupler optimized for normal incidence and numerically demonstrate near-unity coupling in a standard 220-nm-thick silicon-on-insulator (SOI) technology. Our design breaks the vertical symmetry within the grating region by implementing three scattering sites per local period. This technique removes the need for bottom reflectors or additional material layers and can be realized using only two lithography masks.

Experimentally realized in situ backpropagation for deep learning in photonic neural networks.

Integrated photonic neural networks provide a promising platform for energy-efficient, high-throughput machine learning with extensive scientific and commercial applications. Photonic neural networks efficiently transform optically encoded inputs using Mach-Zehnder interferometer mesh networks interleaved with nonlinearities. We experimentally trained a three-layer, four-port silicon photonic neural network with programmable phase shifters and optical power monitoring to solve classification tasks using "in situ backpropagation," a photonic analog of the most popular method to train conventional neural networks.

Power monitoring in a feedforward photonic network using two output detectors.

Programmable feedforward photonic meshes of Mach-Zehnder interferometers are computational optical circuits that have many classical and quantum computing applications including machine learning, sensing, and telecommunications. Such devices can form the basis of energy-efficient photonic neural networks, which solve complex tasks using photonics-accelerated matrix multiplication on a chip, and which may require calibration and training mechanisms. Such training can benefit from internal optical power monitoring and physical gradient measurement for optimizing controllable phase shifts to maximize some task merit function.

Experimental realization of arbitrary activation functions for optical neural networks.

We experimentally demonstrate an on-chip electro-optic circuit for realizing arbitrary nonlinear activation functions for optical neural networks (ONNs). The circuit operates by converting a small portion of the input optical signal into an electrical signal and modulating the intensity of the remaining optical signal. Electrical signal processing allows the activation function circuit to realize any optical-to-optical nonlinearity that does not require amplification.

Automated Cell Segmentation for Quantitative Phase Microscopy.

Automated cell segmentation and tracking is essential for dynamic studies of cellular morphology, movement, and interactions as well as other cellular behaviors. However, accurate, automated, and easy-to-use cell segmentation remains a challenge, especially in cases of high cell densities, where discrete boundaries are not easily discernable. Here, we present a fully automated segmentation algorithm that iteratively segments cells based on the observed distribution of optical cell volumes measured by quantitative phase microscopy.

Choosing Between Unicompartmental and Total Knee Replacement: What Can Economic Evaluations Tell Us? A Systematic Review.

Background And Objective: Patients with anteromedial arthritis who require a knee replacement could receive either a unicompartmental knee replacement (UKR) or a total knee replacement (TKR). This review has been undertaken to identify economic evaluations comparing UKR and TKR, evaluate the approaches that were taken in the studies, assess the quality of reporting of these evaluations, and consider what they can tell us about the relative value for money of the procedures.

Methods: A search of MEDLINE, EMBASE and the Centre for Reviews and Dissemination National Health Service Economic Evaluation Database was undertaken in January 2016 to identify relevant studies.

Standardization and validation of objective structured practical examination in pharmacology: Our experience and lessons learned.

Objectives: The present study is an attempt to standardize and establish validity and reliability of objective structured practical examination (OSPE) as a tool of assessment in pharmacology.

Methods: The individual stations were standardized by establishing the blueprint of assessment, checklists for individual OSPE stations, and a review and revision of existing OSPE stations through intensive focus group discussions. Face and content validity was established by subject nonexperts and experts, respectively.

Hydroxychloroquine-induced erythroderma.

Erythroderma is characterized by diffuse erythema and scaling of the skin involving more than 90% of the total body skin surface area. Drug-induced erythroderma has rarely been reported with hydroxychloroquine. We report a case of a 50-year-old female patient, with systemic lupus erythematosus, who developed itchy lesions all over the body 1 month after starting treatment with hydroxychloroquine.

Evaluation of polypharmacy and appropriateness of prescription in geriatric patients: A cross-sectional study at a tertiary care hospital.

Objectives: To assess the polypharmacy and appropriateness of prescriptions in geriatric patients in a tertiary care hospital.

Methods: An observational study was done in geriatric patients (>60 years) of either gender. The data collected from patients included: Socio-demographic data such as age, gender, marital status, educational status, socioeconomic status, occupation, nutritional status, history of alcohol/smoking, exercise history, details of comorbid diseases, medication history, findings of clinical examination etc.

Spatiotemporal Reconstruction of the Human Blastocyst by Single-Cell Gene-Expression Analysis Informs Induction of Naive Pluripotency.

Human preimplantation embryo development involves complex cellular and molecular events that lead to the establishment of three cell lineages in the blastocyst: trophectoderm, primitive endoderm, and epiblast. Owing to limited resources of biological specimens, our understanding of how the earliest lineage commitments are regulated remains narrow. Here, we examined gene expression in 241 individual cells from early and late human blastocysts to delineate dynamic gene-expression changes.

Dynamic and social behaviors of human pluripotent stem cells.

Human pluripotent stem cells (hPSCs) can self-renew or differentiate to diverse cell types, thus providing a platform for basic and clinical applications. However, pluripotent stem cell populations are heterogeneous and functional properties at the single cell level are poorly documented leading to inefficiencies in differentiation and concerns regarding reproducibility and safety. Here, we use non-invasive time-lapse imaging to continuously examine hPSC maintenance and differentiation and to predict cell viability and fate.

Hylleraas hydride binding energy: diatomic electron affinities.

Theoretical adiabatic electron affinities are often considered inaccurate because they are referenced to only a single value. Ground state electron affinities for all the main group elements and homonuclear diatomics were identified recently using the normalized binding energy of the hydrogen atom: [0.75420375(3)/2 = 0.

Do minimally displaced, closed tibial fractures in children need monitoring for compartment syndrome?

Introduction: Acute compartment syndrome (ACS) may be seen following tibial fractures in adults. Although the risk of this complication is thought to be lower in children (especially in those under the age of 12 years) it is routine practice in many units to admit all children with this injury for observation. The aim of this study was to ascertain whether all children under the age of 12 presenting with fractures of the tibia merited admission and to provide recommendations on how to manage these patients based on our experience with this injury.

Long-term results of a total knee prosthesis utilising an all polyethylene tibial component.

Introduction: The aim of this study was to assess the long-term performance of a cemented total knee replacement utilising an All Polyethylene Tibial (APT) component and in addition to perform an engineering analysis of any failures to help refine surgical technique.

Materials And Methods: A total of 26 patients had a total knee replacement performed using a cemented Depuy Press Fit Condylar (PFC) APT component and a cruciate retaining femoral component. At final review all patients were assessed using The Knee Society Score together with radiographs.

Osteochondral avulsion fracture of the femoral origin of the anterior cruciate ligament in an 11-year-old child.

Although tibial end avulsions of the anterior cruciate ligament are relatively common in clinical practice, avulsions of the femoral end of this ligament are by comparison rare. We present the case of an 11-year-old boy with a bony avulsion injury, which was presumed to have arisen from the tibial insertion of the anterior cruciate ligament but turned out instead to be an osteochondral avulsion fracture of the femoral origin. This unexpected finding that was not detected during preoperative workup resulted in the first attempt at surgical fixation being aborted.

Elective open tracheostomy for patients under prolonged mechanical ventilation-a study.

Objective: To determine the safety of elective open tracheostomy as a routine intensive care unit (ICU) procedure without any selection criteria, considering its peri- and postoperative complications.

Materials And Methods: This is a descriptive study conducted in two hospitals in Davangere for a period of three years between April 2005 and March 2008. 40 patients, both male and female, of all age groups who were under mechanical ventilation in whom open tracheostomy was performed were included in the study.

Delayed anatomical repair of ruptured ulnar collateral ligament injuries of the thumb using a dissolvable polylactic acid bone anchor.

Background: We describe late anatomic repair of complete distal ulnar collateral ligament (UCL) avulsions of the thumb in the absence of metacarpophalangeal joint arthritis using a dissolvable polylactic acid (PLA) bone anchor in two cases, one of which had a Stener lesion.

Methods: Patients presented for surgery respectively at 5 months and 2 years after injury. Preoperative X-ray films showed subtle volar subluxation of the proximal phalanx.

The Glance software package.

We describe the Glance software package, which takes advantage of tablet PC technology to control experiments that require participants to reconstruct complex stimuli, as with the Chase and Simon (1973) chess reconstruction task, and to present tests that require participants to refer briefly to critical displays, as with the digit-symbol task. Participants press the space bar, which allows access to the stimulus and, simultaneously, prohibits drawing on the tablet. At release of the space bar--or optionally, after some period of time--the stimulus is hidden, and the drawing tools are enabled.

Presentation and management of arthritis affecting the trapezio-metacarpal joint.

Arthritis affecting the trapezio-metacarpal joint (TMJ) of the thumb is a very common condition, and in the upper limb represents the site most often requiring surgery for symptomatic osteoarthritis. The condition predominantly affects women, especially those who are post menopausal. Management of the condition initially entails the use of conservative measures.